1. Technical Field
The present invention relates to a dust-disposal assembly applied to machine tools and serves to prevent cutting dust produced in a cutting process from distributing over the air.
2. Description of Related Art
It is known that some materials, such as graphite, wood, composite materials, ceramics and so on, when being machined by a machine tool, tend to generate considerable quantities of cutting dust that is of very fine and very hard particles. If the machine tool is not equipped with a competent dust-disposal assembly, such cutting dust can intrude into the machine tool and may damage machine parts or break circuits in the machine tool.
One conventional dust-proof approach is employing a round water curtain that surrounds the cutting area of the machine tool so that cutting dust of the machine tool can be enclosed by the water curtain from escaping and distributing outward. Then the water flowing from the water curtain and containing the cutting dust is collected, filtered and reused. The conventional dust-proof approach however has some defects.
First, if the water flow is not properly controlled, it may be too strong and damage the workpiece.
Second, the cutting dust will deposit in the water tank and is difficult to clean.
Third, this conventional dust-proof approach is inapplicable when the workpiece must be kept dry (such as graphite parts used in semi-conductor manufacturing process).
An alternative dust-proof solution is dry dust collection. As shown in FIG. 1, a dust-collection pipe 80 is provided beside and moves simultaneously with a spindle of a machine tool. Cutting dust of a workpiece machined by the machine tool thus is collected by the dust-collection pipe 80 and is then filtered in a filtering system. Nevertheless, such dry dust collection suffers from some drawbacks.
Because the dust-collection pipe can not touch the workpiece neither can it cause any obstruction to the automatic tool change process of the machine tool, the dust-collection pipe and its air inlet must remain distant from the spindle and cutting point, resulting in limited dust collecting effect.
Second, when a long cutting tool is used, the air inlet of the dust-collection pipe is even further from the cutting point, causing the dust collecting effect further inferior.
Third, since the cutting area is an open space while air flows faster at a location near the air inlet and flows slower at a location far from the air inlet, the cutting dust far from the air inlet can less or can even not be effectively collected and may then distribute over the open space.
One more conventional dust-proof solution is to use a dust-collection chamber. As can be seen in FIG. 2, a dust-collection chamber 81 is installed in a cutting area of a machine tool. The dust-collection chamber 81 has an opening 82 so that a workpiece to be cut can be placed into the dust-collection chamber 81 while a dust-collection pipe 83 is installed on a wall of the dust-collection chamber. Such dust-collection chamber is yet disadvantageous by some reasons.
First, the opening allows cutting dust of the workpiece to escape therefrom and distribute over the air.
Second, since air flows faster at a location near the air inlet and flows slower at a location far from the air inlet, the cutting dust far from the air inlet can be less or even not collected, resulting in inferior dust collecting effect.
Third, when the workpiece is so high that a cutting point thereof is higher than the air inlet, the cutting dust tends to escape from the opening, causing the dust collecting effect incompetent.